Giant primary liposarcoma of the mediastinum: A case report and review of the literature.

Liposarcoma is a carcinomatous mesenchymal tumor with various histologic features and is the most common soft tissue sarcoma originating in adipose tissue. Liposarcoma commonly occurs in the lower extremities and retroperitoneum but rarely in the mediastinum, specially extending into the thoracic cavity. We report a giant primary liposarcoma of the posterior mediastinum in a 63-year-old female who complained of cough, sputum, and pain in the right chest wall. A computed tomography scan of the chest showed a giant mass of 24 × 15 × 24 cm in the posterior mediastinum of the right thoracic cavity. After a thorough examination, no suspected lipomatous lesions were found elsewhere in the patient's body. The patient underwent a thoracotomy to remove the mediastinal mass through a right thoracic approach. Subsequently, hematoxylin-eosin staining revealed dedifferentiated liposarcoma (DDL), immunohistochemistry showed positive expression of cyclin-dependent kinase 4, and murine double minute 2 (MDM2), in addition, fluorescence hybridization for the MDM2 gene was also positive, which suggested DDL. The patient was discharged without any complications, and no metastasis or recurrence was observed after 19 months of follow-up. To provide a reference for clinical diagnosis and treatment, we reviewed and discussed the literature on primary liposarcoma of the mediastinum.